Article ID: 312355
When you attempt to open an .eml attachment in Outlook Express, either the file may not open or you may receive an error message that states that there is no program associated with this file type.
This behavior can occur if an installed third-party e-mail program has an associated .eml file type.
To resolve this behavior, either run the Msimn executable file with the /reg option to force Outlook Express to re-register its file types, or re-register the .eml file type in My Computer.
To run the Msimn executable file with the /reg option:
Article ID: 312355 - Last Review: June 19, 2014 - Revision: 3.0